Radon decay product particle radioactivity and oxidative stress biomarkers in patients with COPD

• Published in: Environmental research 2024-01, Vol.240 (Pt 2), p.117505-117505, Article 117505
• Main Authors: Romero-Gutierrez, Christopher, Koutrakis, Petros, Liu, Man, Vieira, Carolina L.Z., Coull, Brent A., Maher, Edward F., Zhang, Junfeng (Jim), Garshick, Eric
• Format: Article
• Language: English
• Subjects: Biomarker; Biomarkers; COPD; Humans; Oxidative Stress; Particles; Pulmonary Disease, Chronic Obstructive; Radioactivity; Radon; Radon Daughters; Radon decay; Soot
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2023.117505

Radon decay products include α-radiation emitting radionuclides that attach to airborne particles that have potential to promote oxidative tissue damage after inhalation. To assess associations between α-particle radioactivity (α-PR) with urinary biomarkers of oxidative tissue damage, 140 patients with chronic obstructive pulmonary disease (COPD) had up to four 1-week seasonal assessments (N = 413) of indoor (home) and ambient (central site) PM2.5 and black carbon (BC). Following environmental sampling, urine samples were analyzed for total and free malondialdehyde (MDA), biomarkers of lipid oxidation, and 8-hydroxyl-2′-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage. Particle radioactivity was measured as α-activity on PM2.5 filter samples. Linear mixed-effects regression models adjusted for urinary creatinine and other personal characteristics were used to assess associations. Indoor α-PR was associated with an increase in 8-OhdG (8.53%; 95% CI: 3.12, 14.23); total MDA (5.59%; 95% CI: 0.20, 11.71); and free MDA (2.17%; 95% CI: 2.75, 7.35) per interquartile range (IQR) of α-PR [median 1.25 mBq/m3; IQR 0.64], similar adjusting for PM2.5 or BC. The ratio of indoor/ambient α-PR was positively associated with each biomarker and associations with ambient α-PR were positive but weaker than with indoor concentrations. These findings are consistent with a contribution of radon decay products as measured by α-PR to oxidative stress in patients with COPD, with a greater contribution of indoor radon decay products. [Display omitted] •α-particle radioactivity (α-PR) is associated with oxidative stress in COPD patients.•Associations with indoor α-PR are stronger than with ambient α-PR.•Since α-PR originates from radon decay, radon mitigation may be beneficial.